Intel Extensible Firmware Interface User Manual

Page 175

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Services — Boot Services

Version 1.10

12/01/02

5-77

Most images are loaded by the boot manager. When an EFI application or driver is installed, the
installation procedure registers itself with the boot manager for loading. However, in some cases
an application or driver may want to programmatically load and start another EFI image. This can
be done with the

LoadImage()

and

StartImage()

interfaces. Drivers may only load

applications during the driver’s initialization entry point. Table 5-9 lists the functions that make up
Image Services.

Table 5-9.

Image Functions

Name

Type

Description

LoadImage

Boot

Loads an EFI image into memory.

StartImage

Boot

Transfers control to a loaded image’s entry point.

UnloadImage

Boot

Unloads an image.

EFI_IMAGE_ENTRY_POINT

Boot

Prototype of an EFI Image’s entry point.

Exit

Boot

Exits the image’s entry point.

ExitBootServices

Boot

Terminates boot services.

The Image boot services have been modified to take advantage of the information that is now being
tracked with the

OpenProtocol()

and

CloseProtocol()

boot services. Since the usage of

protocol interfaces is being tracked with these new boot services, it is now possible to automatically
close protocol interfaces when an EFI Application or an EFI Driver is unloaded or exited.

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